Module development and code questions

I'm looking for documentation on creating product types for the ecommerce suite. In particular I'm looking for productapi operations.

I need a feedback/rating system for the registered members/users of my site (www.comactents.org), basically so members can take into account the ratings of other members when deciding whether to work with them in organising an event. I'd like for users to be able to click on a username and get a button or tab that allows them to view the ratings and comments other users have left for that user (a bit like amazons user profiles where you get a star rating and buyers leave feedback, only in this case it would be collaborators instead of buyers).

I don't know whether I need to write a new module or if I'd be better off stringing together a number of already available ones. I've written PhP in the past but it's been a while :) I've installed the volunteers module in my 4.6.1 drupal site, but that only seems to allow volunteer coordinators, of which there can only be one (I think) to view feedback. I need less centralized viewing and commenting control for user ratings... The guestbook module sounds like it could be useful for this purpose but I don't want users to be able to delete feedback without moderator aproval... One idea I had was to have a page node automatically ascociated with each user (not sure how to do that yet) and use the comments for that page as feedback and maybe one of the voting modules to have a vote for the page which represents the user...

any tips or other suggestions very, very welcome!

2checkout addon for e-commerce module
is someone work on this feature?
maybe i can accelerate this process with some donations?

Does anybody know how to display the information from the summary module? I can configure it but how do i show it?

I want to develop a block for site that allows me to post my my Digg.com data onto it. An example of this would be http://www.kevinrose.com. Digg has a tool that creates html that get's your digg data from their servers. I have a page with this data on my site (http://www.jonhoweonline.com/old/testfeed/feed.html). From what I've read on creating modules, this shouldn't be that hard.

Copied (and editied) from http://drupal.org/node/25764 :

How might I, in my Drupal 4.6.1 site, set a default term that is automatically selected when a enters a create-blog-entry form? (Right now the first term appears to be selected by default, and I want to change this to a site-admin-programmable selection.)

I do not see any capability for this in admin/taxonomy/edit/vocabulary/*.

If no capability exists, can anyone provide pointers as to where/how I might update the code to do so?